Area Forecast Discussion
Issued by NWS Marquette, MI
FXUS63 KMQT 280924
Area Forecast Discussion
National Weather Service Marquette MI
424 AM EST Mon Nov 28 2016
.SHORT TERM...(This evening through Monday)
Issued at 356 PM EST SUN NOV 27 2016
WV imagery and RAP analysis indicated a mid/upper level trough over
much of the wrn CONUS, from the Rockies into the wrn plains. A
vigorous lead shortwave was lifting northeast into wrn IA. At the
surface, se winds were increasing between a 989 mb low over sw
Nebraska and a ridge from Quebec into the ern Great Lakes. With
daytime warming, low level moisture trapped below a 1k-2k ft
inversion has lifted to a low stratus deck over most of the cwa
except over portions of the west where downslope se flow was
The short range models were in good agreement with the
progression/onset of the rain ahead of the IA shrtwv and surge of
295k-305k isentropic lift. Expect the rain developing from sw to ne
between 06z-12z to taper off during the morning after the initial
band moves through. Although the mid level moisture will depart
during the day, continued low level isentropic lift will maintain
some light rain or drizzle through most of the day, with lower
amounts and coverage near Lake Superior where the strongest
downslope wind prevails. Fog may thicken again tonight with the loss
of sfc heating but with the rain moving in, should not be as dense
into Monday as it was this morning. Temps will remain steady or
slowly rise tonight and then climb just a few degrees to the lower
to mid 40s Monday.
.LONG TERM...(Tuesday through Sunday)
Issued at 424 AM EST MON NOV 28 2016
Tuesday: The most significant issue Tuesday morning will be a
reinforcing shot of energy that will slide north and eastward from
northern Lower Michigan into southern Ontario. This wave of energy
will drag an associated surface lobe of low pressure across the same
area. The occluded front, stretching between the aforementioned
feature and the vertically stacked low over MN, will slide from
southwest to northeast, clearing the area between 15Z/29 18Z/29. The
better forcing will be will be over the east half and Lake Superior
before 15Z and then quickly slide out of the area with the
aforemention features. At this point, not expect more than an
additional 0.1 to 0.2 inches of additional rainfall over the east
half and the Keweenaw through the morning hours. The deep layer
moisture exits the area with the occluded front through the
afternoon, which should make for a dry afternoon with some breaks in
the clouds expected, especially across the south central and east.
Highs will be well above normal over the east half with most
locations expected to be in the upper 40s to around 50, while the
west half stays mainly in the low to mid 40s.
Tuesday night into Wednesday night: As the occluded front continues
to slowly slide north and east, the area should continue to remain
dry Tuesday night with increasing cloud cover once again ahead of
the next system. The next shot of energy is progged to slide near
the eastern U.P. late Tuesday night through Wednesday
evening.Theadded deeper moisture along with increased forcing, will
allow for another chance of showers moving through the area.
Additionally, the aforementioned occluded low will begin to slide
across the western U.P. by Wednesday afternoon, which will begin to
introduce precip chances over the far west once again. By that time,
cooler air will begin to move in aloft which may allow some snow to
mix in with the rain at times over the far west late Wednesday
afternoon into Wednesday night.
Thursday through the extended: The closed low will slowly meander
through the Upper Great Lakes region through Friday morning before
sliding out of the area Friday night into the weekend. As this
happens, colder air will begin to filter into the region, at the
surface and aloft, allowing the rain to transition to snow.
Currently it looks like the north to northwest wind favored
snowbelts would be most likely to see the best chances for
precipitation. It does look like temperatures overall will trend
colder during this time period and 850mb temperatures are progged to
cool to the -6C to -8C range. Models begin to differ beyond Friday
afternoon, with the EC placing a ridge over the area while the GFS
has a trough over the area Saturday into Sunday, before both
aligning with a slight troughing pattern form Monday. At this point
will stick with a consensus of the models for the late part of the
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1235 AM EST MON NOV 28 2016
IFR/low-end MVFR conditions to prevail at KSAW and KCMX through the
forecast with KSAW and KIWD experiencing some LIFR ceilings at times
during the daylight hours, but especially once the sun sets Monday
evening. Areas of rain continues to spread toward the region and
will persist through Monday evening as a very moist SE flow
continues. Winds to be gusty through the daylight hours with the
highest gusts reaching near 28 knots at KCMX due to channelized flow
there. Gusts to reach into the 20-25 knot range at KSAW and KIWD
during the day before diminishing in the late afternoon.
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 356 PM EST SUN NOV 27 2016
High pressure over the ern Great Lakes will shift to the east
tonight as low pressure deepens across the northern plains into the
upper midwest. This will result in a tight pressure gradient
developing across the northern Great Lakes creating gales overnight.
Gales to 40kt are expected across all of Lake Superior spreading
west to east, but the gradient will slacken earliest across the far
west. Further east the gradient will remain tight, with gales
lingering through Mon night. The low pressure system will linger
over the upper midwest Tuesday into Wednesday. However the pressure
gradient is not expected to be as tight and allow winds to diminish
below 25kt by Tuesday evening. Northerly winds to around 25 knots may
develop Thursday as the slow moving low moves to the east of Lake
Superior into Quebec.
Gale Warning until 10 AM EST Tuesday for LSZ249>251-266-267.
Gale Warning until 8 AM EST /7 AM CST/ this morning for LSZ162.
Gale Warning until 4 AM EST Tuesday for LSZ243-244-264.
Gale Warning until midnight EST /11 PM CST/ tonight for
Gale Warning until 4 AM EST Tuesday for LMZ221-248-250.